Simple 2 hz generator

Thread Starter

FroceMaster

Joined Jan 28, 2012
578
Hi.
Need to make a curcuit where i have this.
A Transistor that normaly is "open" when Base is feed with 5v over resistor,
When i put the BASE low, the transistor should start "flashing" around 2 times per second, (dont care if 1 or 5 times,,) Precission not matter..

I know from "old" days i could use a simple NAND Smith trigger to make that freqency, but cant remeber how,
Any clues in how to get this working ?
 

Thread Starter

FroceMaster

Joined Jan 28, 2012
578
Something like this ?Astabil.png
Gives me around 10 hz, a little to fast but it's ok. Could chenge R8 to 20k, will give blinking at 220 ms ~~5 hz,
Or are I totally wrong ?
 

Dodgydave

Joined Jun 22, 2012
9,090
Your 555 is drawn wrong, link pins 2,6. Pin 1 is Ground you don't need R9, dont use pin 7.
Yes it will work with the cmos gate, OR you can use pin 4 to do the same job.
 

AnalogKid

Joined Aug 1, 2013
8,389
Note that for all of the circuits presented so far, the first half cycle will be significantly wider than all succeeding half cycles.

ak
 
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